The present invention relates to a method for industrially, efficiently, and easily preparing a tertiary hydrocarbon-silyl compound.
An article (J. Org. Chem., 1954, 43, p.3649) discloses a method for bonding a tertiary hydrocarbon group to a silicon atom in which a tertiary alkyl lithium is used. According to this method, a tertiary alkyl lithium is first prepared and then reacted with a silicon atom containing compound. The preparation of such a tertiary alkyl lithium requires the steps of melting metal lithium having a high melting point on the order of 190.degree. C. and then dispersing the molten lithium in an organic solvent in the form of particles having a diameter of several micrometers to perform alkylation. Delicate care is required for handling metal lithium used in this method because of the very high activity thereof. For this reason, the use of a particular apparatus is required for the preparation of the tertiary alkyl lithium. Moreover, the tertiary alkyl lithium spontaneously ignites by simply exposed to the air and handling of a large amount thereof is accompanied with various disadvantages including high danger.
Under such circumstances, Japanese Patent Provisional Publication No. 60-222492 discloses a method for preparing tertiary hydrocarbon-silyl compounds which does not require the use of a process for preparing such a tertiary alkyl lithium compound.
According to the method of this patent publication, a tertiary hydrocarbon-silyl compound is prepared by reacting a hydrogen halogenosilane, in which hydrogen and halogen atoms are directly bonded to the silicon atom, with a tertiary alkyl Grignard reagent. The tertiary Grignard reagent can be prepared without use of any particular apparatus and does not suffer from the problem of spontaneous ignition. For this reason, the preparation of tertiary hydrocarbon-silyl compound according to this method has been believed to be hopeful.
However, the reaction rate achieved by this method is too late. In particular, it is difficult to complete the reaction when solvents other than ethers are used and, therefore, the production efficiency thereof is substantially low.